Authorities in the Upstate were called to four bomb threats at Walmart stores on Tuesday.

Bomb threats at two Spartanburg Walmarts

The first bomb threat was called into the Walmart on Dorman Centre Drive. Police were notified of the call at 4:50 p.m. Five minutes later, police received a call that a similar threat was made against the Walmart on East Main Street.

According to incident reports, an employee working in the fitting room of the Dorman Centre store answered the phone and said a man with a "computerized sound" vernacular used a code known to Walmart workers to indicate he was calling about a bomb threat. The caller reportedly stated he was calling from the store's pharmacy and that the bomb was in the electronics department. The call registered from an unknown number.

Five minutes later, incident reports indicate that a male called the East Main Street store and repeated the same threat.

Both stores were evacuated. K-9s and reinforcements from the Spartanburg County Sheriff's Office responded to both stores and determined there were no explosives present.

Just before 7 p.m., law enforcement at Dorman Centre were clearing the scene but said they would be conducting periodic checks at the facility through the night. Employees were cleared to return to work.

On Wednesday, Major Art Littlejohn with the Spartanburg Police Department said investigators were interviewing Walmart employees and using technology to try and trace the phone call.

Bomb threat at Powdersville Walmart

The Anderson County Sheriff's Office confirmed deputies also responded to a bomb threat at the Walmart in Powdersville on Anderson Road around 5:10 p.m.

According to the incident report, Anderson County deputies said the store received an anonymous call regarding a bomb in the electronics department. Deputies said the caller used the same code Walmart employees know for a bomb as the code used in the Spartanburg threats.

When the employee who received the threat contacted the home office, deputies said the company told him they had been notified of several threats in the surrounding area.

Darrell Hill with the Anderson County Sheriff's Office said the agency was still investigating. He said bomb teams swept the Walmart but found no threats.

Both Hill and Littlejohn said their investigators would be working with the other agencies to determine if the incidents are connected.

Bomb threat at Simpsonville Walmart

The Simpsonville Police Department said officers were dispatched to a bomb threat at the Walmart on Grandview Drive on Tuesday evening around 6:10 p.m. The investigation is ongoing and details are limited at this time.